(1) Field of the Invention
The present invention relates to a device for positioning at a reaction plate, the device being configured to seat a reaction vessel at the reaction plate.
(2) Description of the Related Art
Laboratory based chemical reactions are typically carried out in a reaction vessel and where the reaction medium is liquid based, the reaction vessel is typically a round bottomed glass flask, commonly borosilicate, which is sold under the brand name Pyrex® by Corning of Corning, N.Y.
In order to drive the reaction heat is supplied to the reaction vessel which in turn transfers the heat to the reaction medium. The common bunsen burner represents one of the more primitive sources of heat used in the laboratory to heat reaction vessels. A further example is the commonly used oil bath in which the oil is heated by heating elements located within the bath. Oil baths have found particular use where elevated temperatures are required.
When used within a laboratory environment, the naked flame of the bunsen burner is particularly hazardous as it may serve as an ignition source for flammable solids, liquids or vapour. Oil baths pose a number of significant hazards. Firstly, the viscosity of the oil decreases when heated and spillage or splattering of the heated oil commonly results in skin burns or provides an ignition source. However, one of the more frequent accidents associated with oil baths stems from overheating of the oil resulting in ignition or explosion.
Hotplates and hotplate stirrers have been available for sometime and represent significantly safer laboratory heat sources. Hotplate stirrers operate by generating a rotating electromagnetic field in the region of the hotplate which induces a rotation effect on a magnetised stirring bar positioned within the liquid to be stirred. Resistance heating elements positioned in contact with the hotplate provide a means for heating the substantially planar working surface. Heat is supplied from the hotplate either directly to the reaction vessel, in contact with the hotplate, or via a liquid, typically an oil bath, positioned on the hotplate working surface. When used in combination with an oil bath, the significant risks posed to laboratory personnel remerge. Where a liquid/oil bath is not used the limited surface contact area between the planar hotplate and the curved flask provides for inefficient heat transfer and a limited heating effect.
One known device includes an adapter block constructed from aluminum or stainless steel for positioning over a stirrer hotplate. The adapter block comprises a plurality of recesses, each recess being configured to seat and partially house a reaction vessel. As a result of the extended surface contact area between the adapter block and reaction vessel, heat generated by the hotplate is efficiently transferred to the reaction medium within the reaction vessel.
The known device described above is specifically designed for parallel synthesis involving the simultaneous heating and stirring of multiple reaction vessels positioned outside the perimeter of the hotplate. This known adapter block is specifically designed for use with test tube or boiling tube type reaction vessels having a substantially elongate shape. Additionally, as the reaction vessels are located outside the perimeter of the reaction plate the rotational effect imparted to the magnetised stirring bar within each reaction vessel is reduced. This may be a particular problem where the reaction medium is particularly viscous.